This S-2702 manual from April of 1931 is for the Eisemann GV-4 magneto with the IS-6 impulse coupler Caterpillar application .
Note how plug wires are to be connected. Mr Eisemann did not make it easy.
There were some later versions fo the GV4 that had taller distributor posts and would accept the common plug in wire ends.
Always be sure that the mag impulse coupler does not crowd against the float and the tractor drive hub as described above. This will stress the impulse coupler and may cause the impulse to not engage and retard the spark when starting causing an armbreaker.
Your mag is probably out of warranty.
Sticky goo from deteriorated insulation varnish.
This is one that suffered from sticky goo from deteriorated armature insulation and got a mighty crank. The shuttle pole shoes were glued to the stationary poleshoes and the steel driveshaft turned in the brass endcap and dug into the condenser.
If you savour the sights and sounds of power of the past come join us this …
Many a restorer will savour the conquest of a rusted solid mass of iron …